Research Projects

Malaria remains a major problem in many developing countries, with Plasmodium falciparum accounting for the majority of malaria-related deaths (WHO, 2015). The most difficult challenge in malaria control and elimination is widespread resistance to most conventional drugs. Recently, alarming reports of resistance to artemisinin, a frontline malaria drug, have been reported in Southeast Asia (Dondorp et al., 2009; Amaratunga et al., 2012; Smith et al., 2014; Menard and Ariey, 2015), which is the epicentre of anti-malarial drug resistance, as well as in India Das et al., 2018). Population genomics studies have identified mutations in Kelch13 (K13) gene as a molecular marker for artemisinin resistance (Miotto et al., 2015). The K13 mutant parasites are reported to have reduced hemoglobin endocytosis, slow growth, damaged cellular components and heightened stress response such as unfolded protein response and oxidative stress in the parasite (Birnbaum et al., 2020; Mok et al., 2015). The enhanced lipid metabolism, intracellular trafficking of PI3P-rich vesicles to clear the cellular proteopathy is also reported to have major contribution in artemisinin resistance (Bhattacharjee et al., 2018; Rawat et al., 2022). However, recently, several studies have reported emergence of K13-independent artemisinin resistance from central India (Mishra et al. 2016, Kumar et al. 2019, Das et al. 2021, Pradhan et al. 2022) and Africa. To explore the genetic territory of artemisinin resistance, we used genomic SNP datasets from the MalariaGEN Network (The Pf3K project) from 2,517 isolates from 15 countries to dissect the prevalence, geographical distribution, and co-existing patterns of genetic markers associated with/enabling artemisinin resistance. Interestingly, we identified maximum number of mutations in a novel putative gene named α-ß hydrolase, PF3D7_1328500 (Rawat et al., 2022). Coincidently, in another study, when we performed a large scale whole genome sequencing and analysis of P. falciparum samples (53 isolates) from Kolkata region which has previously shown to have 10-15 % definitive artemisinin resistance, again we observed a large number of mutations in α-ß hydrolase gene but not in the K13 (Choubey et al., 2023, MS under review). In silico analysis suggests that the α-ß hydrolase is a lipase and may have an important role in artemisinin resistance via PI3P pathway as lipid metabolizing enzymes are commonly known to harbor the α/β hydrolase fold. In the proposed study, we aim to understand the role of α/β hydrolase in regulating artemisinin sensitivity in P. falciparum. The study involves determining its catalytic activity and gene knockout studies to ascertain the change in metabolism and lipid profiles in artemisinin resistant phenotypes. The findings will enhance our understanding about the generation of artemisinin resistance and may establish α/β hydrolase as a novel marker for K13 independent artemisinin resistance.